Dynamo-electric-machine construction



May 13. 1924. 1,494,041

R. B. WILLIAMSON DYNAMO ELECTRIC HIAGI'IIIIEI CONSTRUCTION Filed Dec. 17. 1921 Patented May 13, 1924.

UNITED STATES PATENT OFFICE.

ROBERT B. WILLIAMSON, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CHALMERS MANUFACTURING COMPANY, OF MILWAUKEE, WISCONSIN, A. CORPORATION OF DELAWARE.

DYNAMO-ELECTRIC-MACHINE CONSTRUCTION.

Application filed December 17, 1921.

To all w/iomit may concern.

Be it known that ROBERT E. IVILLIAMSON,

a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of WVisconsin, has invented a certain new and useful Improvement in Dynamo- Eleetric-l\fachine Constructions, of which the following is a specification.

This invention relates in general to dynamo-electric machine construction, and has particular relation to features of core construction and the arrangement of windings in slots of the core; and it contemplates an improved construction which provides increased ventilation of the core and the windings, and also facilitates removal of layers of the windings from their active positions in the slots.

In accordance with the ordinary design and construction of core elements of dynamo-electric machines and the ordinary arrangement of windings in the slots thereof, the core is built up of laminations arranged in a plurality of axially separated groups, the radial spaces between the groups constituting ventilatingconduits for the passage of air currents, and the windings are disposed in a plurality of layers in the slots, with the inner or'bottom layer against 30 the bottom or inner end of the slot. The

outer layers of the windings are in immediate contact with the inner layers, with or without some solid insulating material,

other than the normal covering of the con- 3 ductors, between the layers. The portions of the assembled core and winding structure which become heated to the greatest extent are those portions of the winding most thoroughly embedded in the material of the'core. The effects of such ordinary design and construction are that the radial air spaces constitute the sole ventilating means for conducting heat from the interior portions of the core and its windings, this conduction of heat being from the surfaces of the core and those relatively small portions of the winding surface that are located in and are thus in the direct path of air passing through these radial ventilating ducts.

A further undesirable feature of the ordinary design and construction of cores and the arrangement of windings in a plurality of layers in the slots of a core, especially in a large machine having a core of great Serial No. 523,172.

axial length, is that the removal from a slot of an outer layer of the winding, as for purposes of inspection or repair, is exceedingly difficult. The conductor is very liable to bind along the sides of the slot, for the reason, among others, that it is usually forced into position, and because an outer layer conductor can be removed from the slot only with great difficulty and great danger of the bending, distorting or injuring the insulation of the conductor.

In accordance with the general provisions of the invention, outer layers of the winding in the slots are spaced from inner layers thereof by improved means that provide for effective ventilation of interior portions of the core and winding, and it is possible to remove an outer layer conductor from a slot by applying removing pressure thereto at spaced points within the body of the core, thus insuring ready removal with the least liability of damage to the coil.

It is an object of this invention to provide an improved design and construction of dynamo-electric machine which insures effective ventilation of the core and wind ing disposed in slots of the core, and wherein removal of outer layers of the winding from the core slots may be readily accomplished with least liability of damage to the winding.

This and other objects and advantages are attained by this invention, the various novel features of which will be apparent from the description and drawings, disclosing one embodiment of the invention, and will be more particularly pointed out in the claims. I

In the accompanying drawings:

Fig. 1 is a verticalsection of a dynamoelectric machine, of the vertical shaft type.

Fig. 2 is an enlarged broken sectional view of a portion of the stator of the machine shown in Fig. 1.

Fig. 3 is a horizontal section, on reduced scale, along the plane of line IIIIII of Fig. 2.

Fig. 4 is a broken vertical sectional view, on reduced scale, along the plane or surface indicated by the line IV IV of Fig. 2.

Fig. 5 is a view similar to Fig. 4:, showing a modification.

In accordance with the disclosure of the drawings, a dynamo-electric, machine com prises a stator 10 upon which a thrust bear ing 11 for a vertical shaft 12 is mounted, the shaft carrying the rotor 13 ofthe machine, indicated herein as the rotating field tion of this invention, the inner and outer layersof the winding are-held in spaced relation throughout the length of the core by means of spacers 24:, preferably of insulating material, and'here shown spaced apart so as to extend over no more than the axial extent of a single group of core laminae. It will be apparent that this arrangement of the spacers leaves free-and open all sides of those portions or the winding lying in the ventilating spaces 17, thus permitting the ready conduction of heat from these portions of the winding. As illustrated,

spacers 24: are usedonly in alternate groups of laminae, leaving the remaining groups free of obstructions between the layers of winding. Due to the fact that the particular machine illustrated is of the vertical shaft type, slight projections 25. are provided upon the upper sides of the spacers 24:, these projectionsbeing located in the radial ventilating spaces 17 and engaging the wall of agroup of laminae to holdthe spacers in operative position against dropping down, during assembling of the outer layer of winding in operative position in the slots. It will be apparent that the wedges 23 are effective to hold the outer layer of the winding in position against the spacers 24 and both layers in operative position within the slots of the core with the desired ventilating spaces between the layers.

While the spacers 2a are shown included in all of the slots of certain groups of laminae and omitted altogether in adjacent groups, it will be apparent the spacers may be included in only alternate slots of any particular group, the spacers being omittedfrom the similar slots in the adjacent groups of laminae, as: shown in Fig. 5.

In the operation of the machine described above, it will be apparent that heat is developed in the core and windings, considerable heating occurring at points in the winding located within the groups of core laminae. A considerable portion of the heat developed in the core and winding is readily carried away through the several open spaces formed between: the severalelayers of the winding and communicating with the substantially unobstructed radial air spaces 17; Even though this interior ventilation is-not secured in all the groups of laminae, certain of these groups including the spacers or wedges 23, there is a considerable lowering of the operating temperature of the core and winding.

The right hand spacer in Fig. 4 is of modified form, the same including slots 26, opening from each end. These slots will permit the conduction of a certain amount of heat away from interior portions of the winding and core immediately adjacent these spacers.

It will likewisebe apparent that the general idea described above as to the provision of spacing meansbetween the several layers of the winding may be applied between the inner layer of the winding and the bot tom or: inner end of the core slot to further facilitate the conduction of heatfrom interior portions ofthe core and winding.

In addition to the desirable ventilating features present in a dynamo-electric machine embodying thisinvention, it will be apparent that'this feature. of spacing an outer layer of the winding froman inner layer thereof while providing open spaces between those portions of the conductors lo: cated in the radial ventilating ducts, is of extreme utility in facilitating the removal of the outer layer from its position in the slot. It will be apparent that it is desirable that the windings have a relatively tight fit in the core slots in order to avoid chattering or vibration, and for this reason, it is usual to force the windings into position under pressure. If, during assembling of the machine, orat a later date for purposes of repair, it becomes necessary to remove an out-' er layer of the winding from the slot, this may be accomplished quite readily'with the design and construction described above. lVheneverit is desired to remove an outer layer of winding, cords 27 may be fished through the ventilating spaces 17 and through the space between the outer and inner layers of winding, as indicated in Fig. 2; and a bar'28 may be inserted through the loops of the several cords 27, the cords being in as great a number and so located as may be desirable under the particular conditions. Pull applied to the bar or-rod 28-eflects the bodily removal of the outer layer of the winding as a whole and thus prevents binding or distortion of this conductor. It will be apparent that this feature of utility which permits ready. removal of the outer layer of the winding without danger of dis.-

torting the sameor injuring the insulation thereof, is one that contributes greatly to-the general desirability and utility of this invention. I

It; will be apparent that the: invention claimed is not limited to the particular details of construction and design shown and described, for obvious modifications will be apparent to a person skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. A dynamo-electric machine element comprising a core provided with slots and made up of a plurality of groups of laminations, said groups being spaced apart axially to provide radial ventilating ducts in the core, conductors disposed in a plurality of layers in said slots, and means for spacing said conductors apart in the slots, said spacing means being disposed and supported within the slots through pressure exerted upon the conductors and leaving substantially open and unobstructed the spaces between the portions of said conductors lying in said ventilating ducts.

2. A dynamo-electric machine element comprising a core provided with slots and made up of a plurality of groups of laminations, said groups being spaced apart axially to provide radial ventilating ducts in the core, conductors disposed in a plurality of layers in said slots, and a plurality of spacing elements separate from said core and disposed within the slots for holding said conductors in spaced relation, the spaces between the portions of said conductors lying in said ventilating ducts being substantially open and unobstructed.

3. A dynamo-electric machine element comprising a core provided with slots and made up of a plurality of groups of laminations, said groups being spaced apart axially to provide radial ventilating ducts in the core, conductors disposed in a plurality of layers in said slots, and a plurality of separate spacing elements distinct from said core and disposed within the slots for holding the conductors in spaced relation, said spacing elements being substantially confined to the groups of laminations, and the spaces between those portions of the conductors located in said ventilating ducts being substantially open and unobstructed.

4. A dynamo-electric machine element comprising a core provided with slots and made up of a plurality of groups of laminae, said groups being spaced apart axially to provide radial ventilating ducts therebetween, conductors disposed in a plurality of layers in said slots, and means for spacing said conductors apart within said slots, said spacing means being structurally independent of said core and disposed within the slots and leaving substantially open andunobstructed the spaces between those portions of said conductors lying in said ventilating ducts and also leaving substantially open and unobstructed the spaces between portions of said conductors lying within certain groups of laminae.

5. A dynamo-electric machine element comprising a core provided with slots and made up of a plurality of groups of laminae, said groups being spaced apart axially to provide radial ventilating ducts therebetween, conductors disposed in a plurality of layers in said slots, and a plurality of separate spacing elements located in only certain of the slots for holding the conductors in spaced relation, the spaces between those portions of said conductors lying in said ventilating ducts being substantially open and unobstructed, and the spaces between the portions of said conductors lying within those groups of laminae unoccupied by said spacing elements being substantially unobstructed and open to communication with the ad jacent ventilating ducts.

6. A dynamo-electric machine element comprising a core provided with slots and made up of a plurality of groups of: laminae, said groups being spaced apart to provide radial ventilating ducts in the core, conductors disposed in a plurality of layers in said slots. means for spacing said layers apart, said spacing means comprising a plurality of separate spacing elements within the slots for holding the conductors therein in spaced relation, and said spacing elements being located in and substantially confined to only alternate groups of laminae and leaving open and unobstructed the spaces be tween those portions of said conductors located within said ventilating ducts.

7. A dynamo-electric machine element comprising a core provided with slots and made up of a plurality of groups of laminae, said groups being spaced apart axially to provide radial ventilating ducts. conductors disposed in a plurality of layers in said slots, means for spacing said layers apart. said spacing means comprising a plurality of separate spacing elements within the slots for holding the conductors therein in spaced relation, said spacing elements being located in and substantially confined to only alternate groups of laminae and the spaces between those portions of said conductors lylng in said ventilating ducts being substantially open and unobstructed. and the spac between the portlons of said conductors lying within those groups of laminae unoccupied by said spacing elements being substantially unobstructed and open to communication with the adjacent ventilating ducts.

In testimony whereof, the signature of the inventor is aflixed hereto.

ROBERT B. WILLIAMSON. 

